N., your son may not have a problem at all that needs medication. The school may need to evaluate him and see if he needs special help. He may be dyslexic or have some other form of learning disability. Before you think I'm saying that he's retarded or stupid, I'm not. Learning disabled children are usually very intelligent, but the material in the school is not presented in a way that they can learn.
I would request, and demand if you have to, that he be evaluated for learning disabilities. If the evaluation shows that he has some abilities that are lower than his peers, then the school is required by law to help him learn the material in the way that helps him succeed. It's called a Free Appropriate Public Education, FAPE for short, and it is required by federal law.
Don't let the school tell you he needs medication, it is illegal for a school to tell you that a child needs medication. That's practicing medicine without a license, but some try to do it. The want the child to doped up so they can ignore the real reason for the behaviors. My son was so frustrated by the lack of help and teachers who told him he was bad because he could not read or write, that he started hiding under his desk to get away from the hurt. After he was evaluated and started getting the help he needed, he had been so upset by school it took six months for him to start smiling again, even at home. Once he realized that he could succeed, he loved school and went back to his normal self.
If your son is found to be needing special services, then you will go and help write up a specific plan for him, called an Individual Education Program, IEP for short. That way the school knows how to best help him and you can make sure they are following the plan.
I say all this from experience. I waited too long for my son to have him evaluated, and he struggled all through school. The sooner these disabilities are caught, the better the child learns and the less behind he becomes as an adult.
If he is found to have a learning disability (I prefer learning difference), and you want help with advocating for him, send me a private message and I'll send you my contact information. I lived this from grades 1-12 with my son, I've seen it all. It is a passion of mine, to help these super students learn.
And, if he does have a learning difference, you will find that he also has a very unique point of view on the world, that is wonderful. The people who see things from a different angle are those that find the new ways to solve problems. They are the "fancy learners", who make a difference in the world.